Also, if you want an aerial view of the plant, you can find it on google maps here.
The introduction to this post is that I'm writing it from the luxury of a rather swanky 5-star hotel in Taipei.
Taiwan is not in a great position with respect to energy. They have few natural resources of their own to utilise - only a few small natural gas fields in the north of the country. Nuclear is a troublesome subject for such an earthquake-prone island, especially after Fukushima. While you might think that such a mountainous island would be a good site for renewables, the regular earthquakes, landslides and typhoons means that maintaining a large number of wind turbines will also prove difficult. As a result, the majority of Taiwan's electricity comes from coal, most of which is imported from Indonesia.
In addition, there is a lot of heavy industry in Taiwan's economy, and especially cement manufacture, which releases a lot of CO2.
Given their vulnerable position with respect to typhoon activity (Taiwan is typically hit by 3 typhoons a year on average), the Taiwan government is very concerned about climate change, and for the reasons outlined above the principal component of its emissions reduction plan is carbon capture and sequestration (CCS). So myself and a number of "experts" in various CCS-related topics have been spending the week discussing CCS with Taiwan's EPA (Environmental Protection Agency) and ITRI (Industry Technology Research Institute) agencies. I was there to discuss issues of injection-induced seismicity, and potential implications for CO2 leakage, which has proved a major public concern as demo injection projects have been proposed.
However, the point of this post is not to discuss induced seismicity. As part of the trip we were given a tour of a cement factory in Heping, Eastern Taiwan. This plant has installed a CO2 capture pilot plant, which removes CO2 from the exhaust gases that come from the factory. I thought I'd share some photos from the tour, as well as some thoughts on my experience (because it was quite some experience).
The cement factory is absolutely enormous. We could see stacks looming over the jungle as we arrived at the train station:
The scale of the factory really has to be seen to be believed. The photos simply don't do it justice - this is a huge construction:
The CO2 capture plant is only a demo stage. It captures 1 ton of CO2 per hour, from a 1.9MW section of the plant (the whole plant is 300MW, so it really is only a small part of the whole plant). The capture plant is quite a large structure in and of itself, but completely dwarfed by the main factory.
The capture plant works using the process of calcination. You start with calcium carbonate, CaCO3 (which is limestone). When heated, this decomposes to calcium oxide, CaO (lime) and CO2. The released CO2 is 99.9% pure, and can be captured and compressed for shipment. The reaction is reversible, so the CaO is reacted with the flue gas, taking in the CO2 to form CaCO3.
So you have a cyclical process - CO2 is separated from the exhaust gases by reaction with CaO in a fluidised bed. The CaCO3 is then moved to a rotating kiln, and heated to give off the pure CO2 as a separate stream. The major cost is in the re-heating, which means that the process costs $40 per ton of CO2.
The captured CO2 is currently being used to enhance the growth of micro-algae that are being used for bio-diesel. The were a few experimental tanks next to the capture plant.
The last one with the disco lights is an experiment to see whether different light wavelengths improve the growth-rates of the algae.
The current plant captures 1 ton of CO2 per hour, which is pretty small beer on the grand scheme of things. The Taiwan government plans to have a larger scale project up and running by 2020. Where this demo is working on a 1.9MW plant, they want to scale this up to a 300MW plant. The hope is that scaling up and improving efficiency will reduce costs to $20 per ton of CO2. The full scale plant will produce far too much CO2 to be used for algae and biofuels.
Instead, the intention is to use as much as possible for enhanced gas recovery (EGR) in the small natural gas fields in northwest Taiwan, and to store whatever remains in deep saline aquifers off the west coast - which is where my seismological knowledge was required to ensure that storage could be achieved safely.
Taiwan has a number of small natural gas fields - which have stored gas safely despite all of the seismicity (Taiwan experiences 20,000 detected earthquakes per year). Taiwan also operates natural gas storage projects - injecting natural gas into saline aquifers for storage, to be removed for use at later dates (usually in the winter when gas is more expensive). If these natural gas fields and storage sites can maintain storage integrity, there is no reason to think that CO2 could not be stored safely. However, as with all such projects, rigorous site characterisation and geomechanical modelling should be conducted before injection starts, and injection should be monitored throughout with a range of geophysical techniques.
I'll close, however, not with geophysics but with some wider thoughts. Much like when I once visited Beijing, this site really shows the scale of the issue we face if we are to reduce human CO2 emissions to a sustainable rate. This cement plant is absolutely, mind-blowingly, huge! It's churning through coal and calcium carbonate, and burping out CO2, at an incredible rate. The amount of energy this plant must consume is huge.
Much of the world's CO2 emissions are forecast to come from countries like Taiwan that are looking to grow their economies substantially, powered mostly by coal. There's simply no way that a plant like the one we visited today can be powered by renewable energy sources. Not a chance. Yet plants like this are absolutely vital to Taiwanese economic development - this is the major employer in the district. Even if we in the west make every effort to move to renewable energy sources, I don't see these as being viable in any significant way for some of these developing nations. Yet when it comes to CO2, the world doesn't care what country emitted it.
It is rather fortunate that my visit today coincided with the release of the House of Commons Energy and Climate Change Select Committee report on CCS, which has urged for the technology to be fast tracked. Without CCS, I don't see how we can otherwise deal with this issue - maintaining economic growth in developing economies while reducing emissions. It is reassuring to see that the Taiwanese (or the government and academia at least) appear to be as keen for CCS as our Select Committee is.